I am using the function in this answer to upload, attach and then [set_the_post_tumbnail]/featured image to a post which I am creating from an RSS feed.
I ran a test and the output is showing that the attachment ID matches my thumbnail ID. I checked in the media library and it is assigning the correct IDs according to get_post_thumbnail_id but the problem is my featured image meta box is not displaying the image through the dashboard or when using [get the post thumbnail] in my template.
Am I missing any steps here? The code is mostly from the answer linked above with a few tests on the end.
global $wp_query; wp_insert_post($my_post); // create a new post $post_id = $wp_query->post->ID; // get the ID for the new post $image_url = $thumbnail; $upload_dir = wp_upload_dir(); $image_data = file_get_contents($image_url); $filename = basename($image_url); if(wp_mkdir_p($upload_dir['path'])) $file = $upload_dir['path'] . '/' . $filename; else $file = $upload_dir['basedir'] . '/' . $filename; file_put_contents($file, $image_data); $wp_filetype = wp_check_filetype($filename, null ); $attachment = array( 'post_mime_type' => $wp_filetype['type'], 'post_title' => sanitize_file_name($filename), 'post_content' => '', 'post_status' => 'inherit' ); $attach_id = wp_insert_attachment( $attachment, $file, $post_id ); require_once(ABSPATH . 'wp-admin/includes/image.php'); $attach_data = wp_generate_attachment_metadata( $attach_id, $file ); wp_update_attachment_metadata( $attach_id, $attach_data ); set_post_thumbnail( $post_id, $attach_id ); echo "Attachment ID: " . $attach_id; $post_thumbnail_id = get_post_thumbnail_id( $post_id ); echo "Thumbnail ID: " . $post_thumbnail_id; get_the_post_thumbnail($post_id, 'full');